Global Patent Index - EP 0288111 A1

EP 0288111 A1 19881026 - Symmetrical electrical snubber circuit.

Title (en)

Symmetrical electrical snubber circuit.

Title (de)

Symmetrische elektrische Dämpferschaltung.

Title (fr)

Circuit électrique et symétrique amortisseur.

Publication

EP 0288111 A1 19881026 (EN)

Application

EP 88200696 A 19880411

Priority

NL 8700918 A 19870416

Abstract (en)

Symmetrical electrical snubber circuit for protecting at least two series-connected switch members (S1; S2) against excessive voltage and current increase during switching. The voltage increase over each of said switch members is limited by a series circuit of a capacitor and an element having diode action (D1, C1; D2, D2) connected in parallel with said switch members. The magnitude of the DC supply voltage is effectively limited by a further series circuit of a capactior and an element having diode action (D3, C3; D4, C4) connected with said switch members. A freewheeling diode (D5, D6) is connected in parallel with each of said switch members. By incorporating a coil (L1, L2) in the supply lines to the switch members, the current increase during switching-on of a switch member is limited. Like this, a symmetrical snubber circuit which is as low in stray inductance as possible is obtained. The energy stored in the coils (L1, L2) as well as the energy stored in the capacitors (C1; C2) being transferred to the further capacitors (C3; C4) due to resonant action. The energy in these further capacitors can then be discharged with the aid of energy transport means (ET). The snubber circuit according to the invention is in essence loss-free.

IPC 1-7

H02M 7/515; H02M 7/538

IPC 8 full level

H02M 1/34 (2007.01); H02M 7/48 (2007.01); H02M 7/487 (2007.01); H02M 7/515 (2007.01); H02M 7/5387 (2007.01)

CPC (source: EP)

H02M 1/34 (2013.01); H02M 7/487 (2013.01); H02M 7/5155 (2013.01); H02M 7/5387 (2013.01); H02M 1/346 (2021.05); Y02B 70/10 (2013.01)

Citation (search report)

Designated contracting state (EPC)

AT BE CH DE ES FR GB GR IT LI LU NL SE

DOCDB simple family (publication)

EP 0288111 A1 19881026; EP 0288111 B1 19920701; AT E77904 T1 19920715; DE 3872434 D1 19920806; DE 3872434 T2 19930304; DK 208988 A 19881017; DK 208988 D0 19880415; ES 2034155 T3 19930401; FI 87956 B 19921130; FI 87956 C 19930310; FI 881742 A0 19880414; FI 881742 A 19881017; NL 8700918 A 19881116; NO 172826 B 19930601; NO 172826 C 19930908; NO 881655 D0 19880415; NO 881655 L 19881017

DOCDB simple family (application)

EP 88200696 A 19880411; AT 88200696 T 19880411; DE 3872434 T 19880411; DK 208988 A 19880415; ES 88200696 T 19880411; FI 881742 A 19880414; NL 8700918 A 19870416; NO 881655 A 19880415